Effect of maternal transmissions on clinical manifestations of myotonic dystrophy
- Niigata Univ. (Japan); and others
The mutation of myotonic dystrophy (DM) has been identified as unstable expansions of trinucleotide CTG repeat, located on chromosome 19q13-3. Although previous investigations have emphasized the strong association of the sizes of the CTG repeat with ages of onset as well as the clinical manifestations, effects of the paternal or maternal transmissions other than CTG repeats on the clinical manifestations in DM have not been evaluated in detail. To investigate how parental transmission affect the DM phenotype, we analyzed 15 cases of paternal transmission and 25 cases of maternal transmission. We have classified DM patients into 4 clinical grades. As in accordance with previous reports, there is a good correlation on sizes of the CTG repeat with their clinical features. The sizes of the CTG repeat in congenital DM patients (4.13{plus_minus}0.221 kbp) (Mean {plus_minus}SEM), who inherited mutant genes from their mothers, were not significantly larger than those of non-congenital DM patients (3.65 {plus_minus}0.36 kbp). As it has been well established that congenital DM patients are born to affected mothers, we investigated to see if there are any parental bias on the clinical manifestations in non-congenital DM. We classified each case into 4 classes depending on the size ranges of the CTG repeat (0 to 1.5 kbp, 1.5 to 3.0 kbp, 3.0 to 4.5 kbp, 4.5 kbp<). In each group of the size ranges of the CTG repeat, the distribution of cases among grades I to III were compared between paternally and maternally transmitted cases. There were statistically significant differences in the distributions of cases among grades I to III for the size ranges of 3 to 4.5 kbp expansions (p<0.01) and over 4.5 kbp expansions (p<0.05) on {chi}{sup 2} test, respectively. The results revealed that maternally transmitted cases tend to show severe phenotypes compared to paternally transmitted ones even if they have similar sizes of CTG repeat.
- OSTI ID:
- 133614
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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